Our present understanding of motor relearning and skill acquisition makes it very clear that an active stage of intensive and speed sensitive training is essential for the development of new movements or skills. The field of rehabilitation is not different in that respect but, unfortunately, in many cases, the requirement for practice cannot be practically fulfilled because of the nature of the impairment, as well as, the lack of tools required to enable the desired movement. For example, a person with a severe paresis of the lower extremities may not be able to practice tasks needed to improve his/her ability to stand-up from sitting. Even with one or two people supporting that individual, the desired freedom of movement may not be achieved to enable the development of the strength and control associated with the standing up motion.
The gradual build-up, reshaping and refinement of motor skills are part of the process of acquiring skills. Skill-acquisition processes have been extensively studied in an effort to better understand what may facilitate the normal acquisition of skills and also the acquisition of skills in the context of rehabilitation programs. Intensive practice gradually leads to the automation of the learned skill and finally to successful incorporation of that skill into daily activities or sports activities, i.e., a process that should no longer be attention demanding.
In order to show progress in the development of the movement/action, the subject should practice efficiently and sufficiently. The question remains of how to provide efficient and sufficient training for standing up from sitting to someone who cannot initiate such movement on his/her own. What is needed is an apparatus that supports and enables such movement in a safe manner i.e. a sit-to-stand assisting device whose main function is to enable the coordinative sequence of efforts associated with the standing up movement even when the training person is otherwise not able to stand up. The repeated practice of standing and squatting would then gradually develop the strength, balance and coordination associated with the skill of standing.
There are presently many people who, even with manual support, are not able to attempt to stand. These people would most likely continue to atrophy, both from a neurological and muscular perspective, with the realistic chance of never being able to stand up again. At present, apparatuses that can allow the training of standing for such extremely weak individuals do not seem readily available. There are devices that lift people to a standing position and others that maintain them in standing position. These devices, however, do not create the optimal learning environment, which is essential for the skill of standing to be retrieved or relearned.
The use of a pulley system to help propel the body upward is demonstrated in U.S. Pat. No. 4,111,414 issued Sep. 5, 1978 and incorporated herein by reference. There, the line of pull is substantially vertical and the goal of the device is to assist an able person to practice pull-ups on a bar. Since the target practice is not standing, there is no knee support. The vertical angle of pull does not allow for the building of pressure on the legs—a pressure essential for the standing up motion. Finally, this device is stationary—connected to the wall—and therefore does not allow for the dynamic practice once standing is achieved, i.e. does not allow the person, once standing, to walk about with support.
There are some inventions that aim at enabling the efforts to stand through the use of pulleys. More common is the use of a pulley to winch up a person to a standing position as disclosed in U.S. Pat. No. 6,139,475, issued Oct. 31, 2000 and incorporated herein by reference. However, this disclosure does not allow for the independent practice of standing up. It also does not have the lower extremity support that would be required for people with extremely weak lower extremities to attempt standing up. The device is geared for ambulation rather than the act of standing up from sitting.
U.S. Pat. No. 5,064,191, issued Nov. 12, 1991 and incorporated herein by reference is another example of the use of pulleys to provide vertical pull but in this case it is a rebound exerciser. Consistent with its intended function, this device does not provide knee support and cannot help propel a person in the motion required to load the lower extremities and subsequently, stand up.
Therefore, it is desirable to provide a machine that can give variable assist to a person who relearns to stand. Thus, the enabling of the desired motion, i.e. standing, would gradually improve the strength, balance and control associated with that movement. It would also be important to add mobility to such device, thus allowing for gradual progression of the learned skills from a static to a dynamic form.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims concluding the Specification.